[FFmpeg-user] ffmpeg compand knobs problem

Beeblebrox zaphod at berentweb.com
Tue May 20 18:11:37 CEST 2014


@Oliver: "I've never used libfdk_aac before ... My audio is almost
always AC3, MPEG1-L3, WAV or raw"
I am not insisting on libfdk_aac format - I just want the most
compressed but best quality format.
http://trac.ffmpeg.org/wiki/AACEncodingGuide advises in FAQ: "Which
encoder should I use? What provides the best quality? A: For AAC-LC
the likely answer is: libfdk_aac > libfaac > Native FFmpeg AAC encoder
(aac) > libvo_aacenc."

However, I just noticed this section (when I was preparing this
email): "libfaac => Freeware Advanced Audio Coder. Requires ffmpeg
configuration with --enable-libfaac --enable-nonfree. Note that you
will not get as good results as with libfdk_aac." There seems to be a
small conflict in the ffmpeg documentation? I can try a different
encoding scheme for test purposes if anyone wishes (specify which
one).

Also, the fact that a cut section of the video encodes very nicely
with libfdk_aac and compand, while the full video does not; perhaps
gives credence to Oliver's theory.

@Moritz: I had mail delivery set to off (now on), and was responding
to my own previous posts whic resulted in the "new thread" problem. I
don't have any of the responses in my mailbox, so I cannot send as
answer. I tried to modify the header to include "In-response-to", but
that did not work well.

  >> We would need your complete command line and the complete,
uncutconsole output of each of your commands
Not sure I understand - as posted previously, "ffmpeg -i day7.mpg -c:a
libfdk_aac -c:v libx264 -preset slow -crf 32 -f mp4 day7.mp4" is the
command & the only command. I stripped the "volume, compand" knobs out
for noise testing, and as advised the background static is created by
the transformation by libfdk_aac. The full console output captured by
scirpt is here:
https://docs.google.com/document/d/1LC0KFvrWCcxHjGZ4KKY2H8MVoWpH2X6_sIJvo9-awn0/edit?usp=sharing

Before trying to get the entire video to upload maybe we can check
whether the compile options are correct? In FreeBSD
(amd64_11-Current), these are stored in a separate options file and
changes (for testing) is no big deal.
OPTIONS_FILE_SET+=AMR_NB
OPTIONS_FILE_SET+=AMR_WB
OPTIONS_FILE_SET+=CDIO
OPTIONS_FILE_SET+=FDK_AAC
OPTIONS_FILE_SET+=FFSERVER
OPTIONS_FILE_SET+=FONTCONFIG
OPTIONS_FILE_SET+=FREETYPE
OPTIONS_FILE_SET+=FREI0R
OPTIONS_FILE_SET+=ICONV
OPTIONS_FILE_SET+=JACK
OPTIONS_FILE_SET+=LIBV4L
OPTIONS_FILE_SET+=OPENCV
OPTIONS_FILE_SET+=OPENJPEG
OPTIONS_FILE_SET+=OPENSSL
OPTIONS_FILE_SET+=OPTIMIZED_CFLAGS
OPTIONS_FILE_SET+=PULSEAUDIO
OPTIONS_FILE_SET+=SCHROEDINGER
OPTIONS_FILE_SET+=SDL
OPTIONS_FILE_SET+=THEORA
OPTIONS_FILE_SET+=VAAPI
OPTIONS_FILE_SET+=VDPAU
OPTIONS_FILE_SET+=VORBIS
OPTIONS_FILE_SET+=VPX
OPTIONS_FILE_SET+=X11GRAB
OPTIONS_FILE_SET+=X264
OPTIONS_FILE_SET+=XVID

OPTIONS_FILE_UNSET+=AACPLUS
OPTIONS_FILE_UNSET+=ALSA
OPTIONS_FILE_UNSET+=ASS
OPTIONS_FILE_UNSET+=CELT
OPTIONS_FILE_UNSET+=DEBUG
OPTIONS_FILE_UNSET+=FAAC
OPTIONS_FILE_UNSET+=GNUTLS
OPTIONS_FILE_UNSET+=GSM
OPTIONS_FILE_UNSET+=LAME
OPTIONS_FILE_UNSET+=LIBBLURAY
OPTIONS_FILE_UNSET+=MODPLUG
OPTIONS_FILE_UNSET+=OPENAL
OPTIONS_FILE_UNSET+=OPUS
OPTIONS_FILE_UNSET+=RTMP
OPTIONS_FILE_UNSET+=SPEEX
OPTIONS_FILE_UNSET+=VO_AACENC
OPTIONS_FILE_UNSET+=VO_AMRWBENC


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